The thing that I find strange is the one system that sounds so darn good with only the cheapest, while the other wants the high price spread.
Several possible explanations come to mind.
Your main system is better able to reproduce the bad as well as the good, and perhaps the expensive cables (which are often designed to be non-neutral) are filtering it out in the main system, while the secondary system can't reproduce it anyway. An example of "the bad" would be what is called "spectral contamination" due to ultrasonic and rf interference, in the paper I linked to in my post early in this thread. A quote from it:
The audio signal degradation caused by ultrasonic and RF interference coupling.... Any non-linearity in the device under test will create complex intermodulation products at new frequencies, collectively called spectral contamination. Because the new frequencies are usually not harmonically related and appear only when audible signals are also present, they behave more like distortions than noise. Generally, listeners describe the audio as "veiled," "grainy" or "lacking detail and ambience."
Also, large diameter cables with thick dielectrics will have greater capacitance than ordinary thinner cables, unless the dielectric material is chosen to have a lower dielectric constant. Although capacitance is often not specified, my impression is that many higher-end cables intentionally have relatively high capacitance, which may have a filtering effect as well.
The inexpensive components, in turn, may have instability problems or other difficulties driving high capacitance cable, or cable which is otherwise unconventional or non-neutral in its parameters.
Different source impedances in the output stages of line-level components will create different sensitivities to cable parameters.
Cable lengths may be different between the two setups; obviously that will affect sensitivity to cable differences.
Just some thoughts that come to mind; there are undoubtedly other reasons that are conceivable as well.
Regards,
-- Al
